In dentistry hardenable dental compositions are often provided as two-component compositions stored in dual-barrel containers. The components are typically dispensed from such containers only shortly before use and mixed to form the hardenable dental composition. Dental compositions provided in that form include, for example, dental impression materials, dental filling materials, and temporary dental restoration materials.
Containers of this type are often connected or connectable with a mixer that mixes the components as they are extruded from the container. The container therefore typically has at a front end an opening for supplying the components from the individual barrels to the mixer. The container on the rear end further typically has or is prepared to receive pistons or plungers inserted in the barrels for forcing the components towards the opening and the mixer.
There are multi-dose containers that have a capacity to store enough composition for multiple uses. Such multi-dose containers typically have exchangeable mixers to allow for replacement of used mixers so that the container is usable each time with a fresh mixer. Typically the used mixer is left on the container after use, and is only replaced by a new mixer immediately prior to the next use of the container. This enables the composition in the used mixer to cover the openings of the barrels while awaiting the next use, which prevents the components in the barrels from being exposed to the environment between successive uses of the container.
For example, U.S. Pat. No. 4,538,920 discloses a dispensing device which has a syringe with an outlet, to which a static mixer is attachable.
It is generally desirable that the components of dental compositions can be stored in the container over a relatively long time without degradation or hardening. It is also desirable that containers as described without substantial modification are compatible to be used with different types of dental compositions. There is also a general need for multi-dose containers that provide a relatively long open-package shelf life for dental compositions. Other desires are to achieve reliable mixing of the components in the mixer, and to achieve a consistent quality of the mixed compositions after hardening.
It is further desired to provide dental compositions in relatively inexpensive containers, for example in containers as they are established on the market.